U.S. patent application number 12/905297 was filed with the patent office on 2011-04-28 for operation input device and method of controlling same.
This patent application is currently assigned to MITSUMI ELECTRIC CO., LTD.. Invention is credited to KENICHI FURUKAWA.
Application Number | 20110096008 12/905297 |
Document ID | / |
Family ID | 43897995 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110096008 |
Kind Code |
A1 |
FURUKAWA; KENICHI |
April 28, 2011 |
OPERATION INPUT DEVICE AND METHOD OF CONTROLLING SAME
Abstract
An operation input device includes a base part including a
placement surface on which an inductor is placed; a displacement
member including a first surface facing the placement surface and a
second surface configured to receive application of a force, and
configured to cause the inductance of the inductor to vary with the
approach of the first surface to the placement surface due to the
application of the force on the second surface; a support member
configured to support the displacement member in such a manner as
to allow the displacement of the displacement member; a detection
part configured to detect a variation in the inductance by feeding
a first pulse signal to the inductor; and a control part configured
to generate a magnetic field to displace the second surface by
feeding a second pulse signal different in phase from the first
pulse signal to the inductor.
Inventors: |
FURUKAWA; KENICHI; (Tokyo,
JP) |
Assignee: |
MITSUMI ELECTRIC CO., LTD.
|
Family ID: |
43897995 |
Appl. No.: |
12/905297 |
Filed: |
October 15, 2010 |
Current U.S.
Class: |
345/173 |
Current CPC
Class: |
G06F 3/0338 20130101;
G06F 3/046 20130101 |
Class at
Publication: |
345/173 |
International
Class: |
G06F 3/041 20060101
G06F003/041 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2009 |
JP |
2009-244805 |
Claims
1. An operation input device configured to receive a force, the
operation input device comprising: a base part including a
placement surface on which an inductor is placed; a displacement
member including a first surface facing the placement surface and a
second surface configured to receive an application of the force,
the displacement member being configured to cause an inductance of
the inductor to vary with an approach of the first surface to the
placement surface due to the application of the force on the second
surface; a support member configured to support the displacement
member in such a manner as to allow a displacement of the
displacement member; a detection part configured to detect a
variation in the inductance by feeding a first pulse signal to the
inductor; and a control part configured to generate a magnetic
field to displace the second surface by feeding a second pulse
signal to the inductor, the second pulse signal being different in
phase from the first pulse signal.
2. The operation input device as claimed in claim 1, wherein the
control part is configured to feed the second pulse signal in
accordance with a result of detecting the variation in the
inductance.
3. The operation input device as claimed in claim 1, wherein the
control part is configured to vary at least one of an amplitude, a
pulse width, a pulse interval, and a number of pulses of the second
pulse signal in accordance with the result of detecting the
variation in the inductance.
4. A method of controlling an operation input device, comprising:
detecting a variation in an inductance of an inductor placed on a
placement surface of a board by feeding a first pulse signal to the
inductor, the variation in the inductance being caused by an
approach of a first surface of a displacement member to the
placement surface due to an application of a force on a second
surface of the displacement member; and generating a magnetic field
to displace the second surface of the displacement member by
feeding a second pulse signal to the inductor, the second pulse
signal being different in phase from the first pulse signal.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is based upon and claims the benefit
of priority of Japanese Patent Application No. 2009-244805, filed
on Oct. 23, 2009, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to operation input
devices that receive an operator's input and methods of controlling
the same, and more particularly to an operation input device
configured to provide an operator with vibrations and a method of
controlling the same.
[0004] 2. Description of the Related Art
[0005] Conventionally, an input device is known that detects an
input position and a pressure at the time of pressing with an
operator's finger using a resistive touchscreen panel and provides
the touchscreen panel with vibrations. (See, for example, Japanese
Laid-Open Patent Application No. 2005-275632.) This input device
detects the input position and the pressure with a voltage
measuring circuit while providing a user with vibrations using a
vibrating motor.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present invention, an
operation input device configured to receive a force includes a
base part including a placement surface on which an inductor is
placed; a displacement member including a first surface facing the
placement surface and a second surface configured to receive an
application of the force, the displacement member being configured
to cause an inductance of the inductor to vary with an approach of
the first surface to the placement surface due to the application
of the force on the second surface; a support member configured to
support the displacement member in such a manner as to allow a
displacement of the displacement member; a detection part
configured to detect a variation in the inductance by feeding a
first pulse signal to the inductor; and a control part configured
to generate a magnetic field to displace the second surface by
feeding a second pulse signal to the inductor, the second pulse
signal being different in phase from the first pulse signal.
[0007] According to one aspect of the present invention, a method
of controlling an operation input device includes detecting a
variation in an inductance of an inductor placed on a placement
surface of a board by feeding a first pulse signal to the inductor,
the variation in the inductance being caused by an approach of a
first surface of a displacement member to the placement surface due
to an application of a force on a second surface of the
displacement member; and generating a magnetic field to displace
the second surface of the displacement member by feeding a second
pulse signal to the inductor, the second pulse signal being
different in phase from the first pulse signal.
[0008] The objects and advantages of the invention will be realized
and attained by means of the elements and combinations particularly
pointed out in the claims.
[0009] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other objects, features and advantages of the present
invention will become more apparent from the following detailed
description when read in conjunction with the accompanying
drawings, in which:
[0011] FIGS. 1A and 1B are diagrams for illustrating an operation
input device according to an embodiment of the present
invention;
[0012] FIG. 2 is an exploded perspective view of a first example of
the operation input device according to the embodiment of the
present invention;
[0013] FIG. 3 is a cross-sectional view of the first example of the
operation input device according to the embodiment of the present
invention;
[0014] FIG. 4 is an exploded perspective view of the first example
of the operation input device in which return springs are provided
according to the embodiment of the present invention;
[0015] FIG. 5 is a cross-sectional view of the first example of the
operation input device in which the return springs are provided
according to the embodiment of the present invention;
[0016] FIG. 6 is a perspective view of the first example of the
operation input device where a key is placed on the return springs
according to the embodiment of the present invention;
[0017] FIG. 7 is a cross-sectional view of the first example of the
operation input device where an operator's finger is placed on the
key according to the embodiment of the present invention;
[0018] FIG. 8 is a cross-sectional view of the first example of the
operation input device where the center of the key is pressed
according to the embodiment of the present invention;
[0019] FIG. 9 is a cross-sectional view of the first example of the
operation input device where the key is pressed at a position in an
x(-) direction according to the embodiment of the present
invention;
[0020] FIG. 10 is a plan view of the first example of the operation
input device where a finger is placed at a position in a 45.degree.
direction in the x-y plane according to the embodiment of the
present invention;
[0021] FIG. 11 is a vector diagram of a force in an xyz space
according to the embodiment of the present invention;
[0022] FIG. 12 is a vector diagram of the force in the xyz space
according to the embodiment of the present invention;
[0023] FIG. 13 is a block diagram illustrating an inductance
detecting circuit configured to detect inductance variations
according to the embodiment of the present invention;
[0024] FIG. 14 is a block diagram illustrating a driving circuit
and a reception circuit of the inductance detecting circuit
according to the embodiment of the present invention;
[0025] FIG. 15 is a chart of waveforms at respective points of FIG.
14 according to the embodiment of the present invention;
[0026] FIG. 16 is a chart of waveforms at a time of causing the
first example of the operation input device to operate with a
control method controlling the first example of the operation input
device into the state illustrated in FIGS. 1A and 1B according to
the embodiment of the present invention;
[0027] FIG. 17 is an exploded view of a second example of the
operation input device according to the embodiment of the present
invention;
[0028] FIG. 18 is a diagram illustrating the key provided with
cores according to the embodiment of the present invention;
[0029] FIG. 19 is a diagram illustrating the positional
relationship of components of the second example of the operation
input device according to the embodiment of the present
invention;
[0030] FIG. 20 is a diagram illustrating an arrangement of a click
spring and the return springs according to the embodiment of the
present invention;
[0031] FIG. 21 is a cross-sectional view of the second example of
the operation input device where an operator's finger is placed on
the key according to the embodiment of the present invention;
and
[0032] FIG. 22 is a cross-sectional view of the second example of
the operation input device where the key is pressed at a position
in an x(-) direction according to the embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] As described above, an input device is known that detects
the input position and the pressure using a resistive touchscreen
panel and provides the touchscreen panel with vibrations. According
to this conventional technique, however, the function of detecting
an operator's force and the function of providing the operator with
vibrations are implemented with separate configurations independent
of each other, so that the input device is likely to be large in
size. Further, the configuration for implementing the vibration
providing function is complicated.
[0034] According to one aspect of the present invention, an
operation input device and a method of controlling the operation
input device are provided that implement the function of detecting
an operator's force and the function of providing the operator with
vibrations with a simple configuration.
[0035] A description is given below, with reference to the
accompanying drawings, of an embodiment of the present
invention.
[0036] Normally, the following relational expression holds with
respect to the inductance L of an inductor such as a coil
(winding):
L=K.mu.n.sup.2S/l,
where K is a coefficient, .mu. is magnetic permeability, n is the
number of turns of the coil, S is the cross-sectional area of the
coil, and l is the magnetic path length of the coil.
[0037] As is clear from this relational expression, the inductance
is caused to vary by a change in the ambient magnetic permeability
or a change in the magnetic path length if the shape-dependent
parameters, that is, the number of turns and the cross-sectional
area of the coil, are fixed. In an operation input device according
to the embodiment of the present invention, this variation in
inductance is used.
[0038] The operation input device of this embodiment is configured
to receive (accept) an operator's force input from a z-axial
direction of a Cartesian coordinate system defined by the x-axis,
y-axis, and z-axis. The z-axial direction refers to a direction
parallel to the z-axis. The operator's force is detected based on a
predetermined signal that varies with variations in inductance.
[0039] Further, the operation input device of this embodiment
causes a current that generates a magnetic field around an inductor
to flow through the inductor. The magnetic field thus generated
causes a displacement that serves to simulate the operator to an
operation surface on which the operator's force is applicable.
[0040] FIGS. 1A and 1B, which are diagrams for illustrating the
operation input device of this embodiment, are side views of the
operation input device, in which part of the configuration of the
operation input device is illustrated with a cross section. FIG. 1A
illustrates an initial state where no magnetic field for causing an
operator to feel a displacement of an operation surface 30b is
generated. FIG. 1B illustrates a state where a magnetic field for
causing the operator to feel a displacement of the operation
surface 30b is generated. The operation input device of this
embodiment includes a board 10, an inductor 20, a displacement
member 30, support members 50A and 50B, a detection part 160, and a
control part 170.
[0041] The board 10 is a base part including a placement surface
10a on which the inductor 20 is placed. The inductor 20 is
illustrated in a cross-sectional view of a coil inductor.
[0042] The displacement member 30, which is provided on a side from
which the operator's force is input relative to the board 10,
includes an opposed surface 30a (first surface) facing (opposed to)
the placement surface 10a and the operation surface 30b (second
surface) on which the operator's force is applicable. The
displacement member 30 is configured to cause the inductance of the
inductor 20 to vary with the approach of the opposed surface 30a to
the placement surface 10a due to application of the operator's
force on the operation surface 30b. A magnetic circuit is formed
between the displacement member 30 and the inductor 20. For
example, part or all of the displacement member 30 is formed of a
material higher in magnetic permeability than air.
[0043] The support members 50A and 50B support the displacement
member 30 so that the displacement member 30 may vary in such a
manner as to vary the interval (distance) between the opposed
surface 30a and the placement surface 10a. For example, the support
members 50A and 50B support the displacement member 30 so that the
interval between the opposed surface 30a and the placement surface
10a changes elastically. By way of example, the support members 50A
and 50B may be spring members, rubber members, sponge members, or
cylinders filled with air or oil. For example, adoption of spring
members makes it possible to reduce weight and simplify a
structure, while employment of rubber members makes it possible to
provide insulation. The support members 50A and 50B may also be
viscous members having viscosity.
[0044] The detection part 160 is configured to detect a variation
in the inductance of the inductor 20 by feeding a first pulse
signal to the inductor 20. The detection part 160 detects a
variation in the inductance of the inductor 20 based on, for
example, a pulse voltage (first pulse voltage) generated across the
inductor 20 by the feeding of a pulse current corresponding to the
first pulse signal (a first pulse current) to the inductor 20. The
position of an application point on the operation surface 30b and
the displacement (amount) of the displacement member 30 may be
calculated based on the detection result of the variation of the
inductance of the inductor 20.
[0045] The control part 170 causes a magnetic field H that
displaces the operation surface 30b to be generated by feeding the
inductor 20 with a second pulse signal different in phase from the
first pulse signal. The magnetic field H generated by the flowing
of a pulse current corresponding to the second pulse signal (a
second pulse current) through the inductor 20 generates an
attraction force F that attracts the displacement member 30 to the
inductor 20. The displacement member 30 having the operation
surface 30b is caused to vibrate by a variation in the magnitude of
the attraction force F generated by the feeding of the second pulse
signal to the inductor 20. That is, the second pulse signal, which
varies temporarily in amplitude, is thus capable of varying the
magnitude of the attraction force F.
[0046] The displacement of the operation surface 30b is caused by
the displacement of the displacement member 30 due to the magnetic
field H. If the attraction force F due to the magnetic field H is
lost or reduced, the displacement member 30 is caused to return to
its initial state illustrated in FIG. 1A by the force (for example,
elastic force) of the support members 50A and 50B to press back the
displacement member 30. Accordingly, the displacement member 30 and
the operation surface 30b are caused to vibrate by the control part
170 causing the magnitude of the attraction force F due to the
magnetic field H to vary continuously. The vibrations of the
displacement member 30 and the operations surface 30b are not
limited to vibrations of two or more back-and-forth motions, and
may be vibrations of a single back-and-forth motion.
[0047] The first pulse signal and the second pulse signal may be
square waves, triangle waves, or sawtooth waves.
[0048] Accordingly, in the case of the operation input device of
this embodiment illustrated in FIGS. 1A and 1B, it is possible to
detect a force and generate vibrations by feeding the same inductor
20 with the first pulse signal and the second pulse signal
different in phase from each other. That is, both the function of
detecting an operator's force and the function of providing the
operator with vibrations may be implemented with a simple
configuration of feeding the inductor 20 with two kinds of pulse
signals without forming a complicated structure. Further, a
component (the inductor 20) may be shared between a configuration
for detecting the operator's force and a configuration for
providing the operator with vibrations. Accordingly, it is possible
to reduce size and costs.
[0049] Next, a description is given of examples of the operation
input device and their controlling methods according to the
embodiment of the present invention.
[0050] FIG. 2 is an exploded perspective view of an operation input
device 1, which is a first example of the operation input device of
this embodiment. FIG. 3 is a cross-sectional view of the operation
input device 1.
[0051] In the following description, the same elements as those of
FIGS. 1A and 1B are referred to by the same reference numerals.
[0052] The operation input device 1 includes the board 10 including
the placement surface 10a on which multiple inductors (four coils
21, 22, 23, and 24 in the case of FIG. 2) are placed. The board 10
is a base part having a placement surface parallel to an x-y plane.
The origin O, which is the point of reference of a
three-dimensional Cartesian coordinate system, is set at a position
a predetermined distance away from the placement surface 10a to a
side from which an operator's force is input (the upper side
relative to the board 10 in the case of FIG. 2). The board 10 may
be a resin board, but may also be a steel plate having sheet steel
or silicon sheet steel as a base material in order to serve as a
yoke.
[0053] The coils 21 through 24 are arranged in a circumferential
direction of a virtual circle formed by connecting points
equidistant from the origin O. It is preferable that the coils 21
through 24 be equally spaced in the circumferential direction in
terms of facilitating calculation of the vectors of an operator's
force. If the coils 21 through 24 have the same characteristics,
the coils 21 through 24 may be arranged to have the same distance
between the centers of gravity of each adjacent two of the coils 21
through 24. The coils 21 through 24 are arranged 90.degree. apart
on the same circle to be positioned in the four directions of x(+),
y(+), x(-), and y(-), respectively. The x(-) direction is at
180.degree. from the x(+) direction in the x-y plane, and the y(-)
direction is at 180.degree. from the y(+) direction in the x-y
plane. The coil 21 is placed on the positive side on the x-axis
relative to the origin O, the coil 22 is placed on the positive
side on the y-axis relative to the origin O, the coil 23 is placed
on the negative side on the x-axis relative to the origin O, and
the coil 24 is placed on the negative side on the y-axis relative
to the origin O.
[0054] Further, the operation input device 1 includes the
displacement member 30, which is a key in this example, provided on
a side from which an operator's force is input relative to the
board 10. The plate-shaped key 30 is placed above the coils 21
through 24 provided on the board 10. The key 30 includes the
opposed surface 30a (the lower surface in FIG. 2) facing (opposed
to) the placement surface 10a on which the coils 21 through 24 are
placed and the operation surface 30b (the upper surface in FIG. 2)
on which the operator's force is applicable. The key 30 is
configured to cause the inductance of at least one of the four
coils 21 through 24 to vary with the approach of the opposed
surface 30a to the placement surface 10a on which the coils 21
through 24 are placed due to application of the operator's force on
the operation surface 30b. In order to cause variations in the
inductance of the coils 21 through 24, the key 30 may be at least
formed of a material higher in magnetic permeability than air. The
relative magnetic permeability of the key 30 is preferably higher
than or equal to 1.001. The key 30 may be magnetic material such as
iron or ferrite. The key 30 may also be resin mixed with powder of
ferrite or the like.
[0055] The key 30 is supported by a case 40 so as to be movable in
the z-axial directions. The case 40 supports the key 30 so as to
allow the key 30 to move in a direction to approach the board 10
from its standby position with application of the operator's force
on the operation surface 30b, the standby position being the
position of the key 30 in a standby state (initial state) where
there is no application of the operator's force on the operation
surface 30b. The case 40 is fixed to the board 10.
[0056] Further, the operation input device 1 includes an elastic
support member configured to elastically support the key 30 in
directions in which the opposed surface 30a of the key 30 and the
placement surface 10a of the board 10 face each other, so that the
interval (distance) between the opposed surface 30a and the
placement surface 10a changes elastically. For example, return
springs 51, 52, 53, and 54 for returning the key 30 to its standby
position may be provided outside (to surround) the coils 21 through
24 on the placement surface 10a of the board 10 as the elastic
support member as illustrated in FIG. 4, FIG. 5, and FIG. 6. The
return springs 51 through 54 are plate-shaped elastic bodies.
[0057] The elastic support member may be provided between the
placement surface 10a of the board 10 and the opposed surface 30a
of the key 30. The elastic support member is configured to
elastically support the key 30 in such a manner as to prevent
application of the operator's force from causing the key 30 to come
into contact with any of the coils 21 through 24. The elastic
support member supports the key 30 in such a manner as to allow the
key 30 to be inclined relative to the x-y plane perpendicular to
the z-axis and to move in the z-axial directions. Further, the
elastic support member may also support the key 30 with the opposed
surface 30a of the key 30 being urged in a direction away from the
placement surface 10a of the board 10.
[0058] The elastic support member is configured to elastically
support the key 30 so that the operation surface 30b of the key 30
is parallel to the x-y plane with no application of the operator's
force on the operation surface 30b. The operation surface 30b of
the key 30 may be a flat surface or a surface formed to be concave
or convex relative to the x-y plane. By changing the shape of the
operation surface 30b as desired, it is possible to improve
operability for the operator. Further, the operation surface 30b of
the key 30 may be circular, elliptical, or polygonal.
[0059] Further, the operation input device 1 includes an output
part 180 (FIGS. 1A and 1B) configured to output an output signal
generated by a change in the inductance of at least one of the
coils 21 through 24 to the detection part 160 (FIGS. 1A and 1B).
This output part 180 is provided for each of the coils 21 through
24 so that variations in inductance caused in the coils 21 through
24 may be detected on a coil-by-coil basis. The output part 180 is
electrically connected to an end portion of each of the coils 21
through 24. For example, an interconnect connected to the end
portion of each of the coils 21 through 24 and a terminal connected
to the interconnect may be provided as the output part 180. In this
case, each terminal is connected to the detection part 160.
[0060] FIG. 7, FIG. 8, and FIG. 9 are diagrams for illustrating
states of the operation input device 1 at the time of the operator
operating the operation input device 1. In each of FIG. 7, FIG. 8,
and FIG. 9, (b) illustrates the position of a finger on the
operation surface 30b of the key 30.
[0061] FIG. 7 illustrates a state where the operator is placing a
finger on the operation surface 30b, which is the rear surface of
the key 30, without applying force. There is no change in the
inductance of each of the coils 21 through 24 in the standby state
of FIG. 7 where there is no downward pressing of the key 30 with a
finger of the operator.
[0062] FIG. 8 illustrates a state where a center portion of the
operation surface 30b of the key 30 is pressed. In the state of
FIG. 8, the distances between the key 30 and the coils 21 through
24 (indicated by D1 and D2 in (a) of FIG. 8) are reduced so that
the inductance of each of the coils 21 through 24 increases. The
distance D1 indicates a distance in the z-axial directions on the
x(+) direction side, which is the positive side of the x-axis. The
distance D2 indicates a distance in the z-axial directions on the
x(-) direction side, which is the negative side of the x-axis. The
amount of pressing of the key 30 at a position in the x-axial
directions may be detected based on the difference between the
inductance of the coil 21 and the inductance of the coil 23. The
amount of pressing of the key 30 at a position in the y-axial
directions may be detected based on the difference between the
inductance of the coil 22 and the inductance of the coil 24. These
amounts of pressing may be detected as analog values. In the state
of FIG. 8, the differences in inductance between the x-axis
directions and the y-axis directions, which are zero or less than
or equal to a preset detection threshold, are determined to be
zero. However, by also calculating the sum of the inductances of
the coils 21 through 24 at the same time, it is possible to detect
the pressing of the center portion of the operation surface 30b of
the key 30 on the z-axis. The amount of pressing of the key 30 with
the center portion of its operation surface 30b being pressed may
also be detected as an analog value.
[0063] FIG. 9 illustrates a state where the key 30 is pressed on
the x(-) direction side (D2<D1). In the state of FIG. 9, it is
possible to detect the presence of the point of application of
pressing at a position in the x(-) direction on the operation
surface 30b of the key 30 based on the difference between the
inductance of the coil 21 and the inductance of the coil 23.
[0064] A description is given, with reference to FIG. 10 through
FIG. 13, of a method of calculating a direction in which a force is
input relative to the origin O (a position of input in the x-y
plane) and the magnitude of the force (the amount of pressing in
the z-axial directions). The detection part 160 (FIGS. 1A and 1B)
calculates the position of input of a force in the x-y plane and
the amount of pressing in the z-axial directions based on
evaluation values representing a change in the x-directional
component and a change in the y-directional component,
respectively, of inductance.
[0065] As illustrated in FIG. 10, in the case of operating the key
30 by pressing a position P (a point of application on the
operation surface 30b of the key 30) in a direction of 45.degree.
in the x-y plane with a finger, a change (difference) in inductance
is caused in each of the x-directional component and the
y-directional component.
[0066] It is possible to increase calculation accuracy and reduce
calculation time by correcting or normalizing in advance the amount
of change in inductance due to application of the operator's force.
Therefore, the inductances of the four coils 21 through 24 in the
state where there is no pressing in any direction in the x-y plane
(standby state) and in the state of a full stroke are prestored in
a memory. The inductances stored in the memory may be values preset
based on design values or values actually measured at the time of
manufacturing, or may be measured based on an instruction signal
from a user at the time of use by the user. Further, the maximum
value of each inductance during use may be learned. Detected values
of inductance vary between the minimum value in the standby state
and the maximum value in the full-stroke state thus obtained. In
measuring inductance in each direction in the x-y plane, the
inductance may be evaluated on a coil-by-coil basis or a difference
in inductance between opposed two of the coils 21 through 24 may be
evaluated. The amount of change in inductance of each of the coils
21 through 24 in response to pressing by the operator is corrected
or normalized using these minimum and maximum values.
[0067] A description is given of a calculation for detecting the
direction of pressing (a position at which pressing is performed)
and the amount of pressing in the x-y plane, taking, as an example,
a case where pressing is performed with a component in each of the
x(+) direction and the y(+) direction as illustrated in FIG.
10.
[0068] The amount of change in the x-directional component of
inductance is detected based on an x-directional difference value,
which is a difference between the corrected or normalized amount of
change in inductance of the coil 21 placed in the x(+) direction
and the corrected or normalized amount of change in inductance of
the coil 23 placed in the x(-) direction. Likewise, the amount of
change in the y-directional component of inductance is detected
based on a y-directional difference value, which is a difference
between the corrected or normalized amount of change in inductance
of the coil 22 placed in the y(+) direction and the corrected or
normalized amount of change in inductance of the coil 24 placed in
the y(-) direction. That is, the x-directional difference value
corresponds to the evaluation value representing the amount of
change in the x-directional component of inductance, and the
y-directional difference value corresponds to the evaluation value
representing the amount of change in the y-directional component of
inductance.
[0069] For example, it is assumed that the x-directional difference
value is calculated to be 0.5 and the y-directional difference
value is calculated to be 0.5 in the state of FIG. 10 in the case
where the above-described correction or normalization is performed
so that the maximum value of the x-directional difference value and
the maximum value of the y--directional difference value are both
1. These two evaluation values are determined as an x-coordinate
vector and a y-coordinate vector. Then, as illustrated in FIG. 11,
a vector resulting from the composition of the two vectors is
calculated in the x-y plane. As illustrated in FIG. 12, the angle
formed by this resultant vector in the x-y plane with a reference
direction (for example, the x(+) direction) is determined as
.THETA..sub.XY. That is, the vector length of the resultant vector
corresponds to the amount of pressing, and the vector angle
.THETA..sub.XY corresponds to the direction of input force.
[0070] In the case of this example, the vector length of the
resultant vector is 0.707 (= (0.5.sup.2+0.5.sup.2)), and the vector
angle .THETA..sub.XY is 45.degree. (=tan.sup.-1 (0.5/0.5)). A
method like this makes it possible to detect all 360.degree.
directions and to detect the amount of pressing. Further, it is
possible to detect pressing in the z-axial (z(-)) direction by
calculating the sum of the inductances and determining the sum as
an evaluation value for the amount of pressing of the entire key 30
in order to detect the case of pressing in the z-axial (z(-))
direction.
[0071] FIG. 13 is a block diagram illustrating an inductance
detecting circuit 100 configured to detect a change (variation) in
inductance. The inductance detecting circuit 100 is a calculation
part configured to detect a change in the inductance of each of the
coils 21 through 24. The inductance detecting circuit 100 includes
a CPU 60, which is a computation part, a driving circuit 66
connected to a first output port 61 of the CPU 60, a multiplexer
(MUX) 68 connected to first ends of the coils 21 through 24, whose
second ends are grounded, and a reception circuit 67, which is
connected to a second output port 62 and an A/D port 63 of the CPU
60. The multiplexer 68 connects the coils 21 through 24 on the
board 10 to the CPU 60 through the shared reception circuit 67 and
driving circuit 66. The connection destination of the multiplexer
68 is switched (uniquely selected) by addressing from the CPU 60
through an address bus 64. Accordingly, the inductances of the
coils 21 through 24 are detected sequentially at different
detection points (times) on a coil-by-coil basis.
[0072] FIG. 14 is a block diagram of the driving circuit 66 and the
reception circuit 67 in FIG. 13. The driving circuit 66 is
configured to cause electric current to flow through each of the
coils 21 through 24 by controlling the output current of a constant
current source 66a in accordance with an output signal from the
output port 61 of the CPU 60. The reception circuit 67 inputs the
voltage generated as a result of causing electric current to flow
through each of the coils 21 through 24 to a peak hold circuit 67b,
which may be replaced with a bottom hold circuit, through an
amplifier (AMP) 67a. A peak value (analog value) held by the peak
hold circuit 67b is input to the A/D port 63 to be converted into a
digital value by an A/D converter (not graphically
illustrated).
[0073] FIG. 15 is a diagram illustrating waveforms at respective
points (V1, I1, V2, and V3) in FIG. 14. A voltage waveform of a
square wave is output from the output port 61 of the CPU 60 as
illustrated in (a) of FIG. 15. This voltage causes the constant
current circuit 66a to cause a constant electric current to flow
through the coil (representing any of the coils 21 through 24) ((b)
of FIG. 15). Thereby, the coil generates a voltage V2 of a
differentiated waveform as illustrated in (c) of FIG. 15. As the
voltage waveform V2, a waveform 2-1 synchronizing with the rise of
the voltage waveform V1 and a waveform 2-2 synchronizing with the
fall of the voltage waveform V1 are obtained. The waveform 2-2 is
opposite in polarity to the waveform 2-1. The amplifier 67a
amplifies the voltage waveform V2 to a size suitable for the
dynamic range of the A/D converter. By performing peak holding or
bottom holding on the voltage waveform V2, the held value is taken
into the A/D converter (the A/D port 63). (See (d) or (e) of FIG.
15.) The amplitude values of the waveforms 2-1 and 2-2 increase in
proportion to the magnitude of the inductance of the coil.
Accordingly, by detecting the amplitude value of the waveform 2-1
or 2-2, it is possible to evaluate the magnitude of the inductance
of each of the coils 21 through 24.
[0074] FIG. 16 is a chart of waveforms at the time of causing the
operation input device 1 to operate with a control method that
controls the operation input device 1 into the states illustrated
in FIGS. 1A and 1B. The detection part 160 and the control part 170
correspond to the inductance detecting circuit 100 illustrated in
FIG. 13. That is, the detection part 160 and the control part 170
are implemented with the single inductance detecting circuit 100. A
description is given, in accordance with the waveform chart of FIG.
16, of a method of controlling the operation input device 1,
referring to FIGS. 1A and 1B, FIG. 13, and FIG. 14 as well.
[0075] The method of controlling the operation input device 1
includes an inductance detecting step of detecting a change in the
inductance of each of the coils 21 through 24 by feeding a first
pulse signal to the coils 21 through 24 on a coil-by-coil basis. In
the inductance detecting step, the CPU 60 of the inductance
detecting circuit 100 outputs a pulse waveform p (pulses p1 through
p9) from the output port 61 as the square-wave voltage waveform V1
as illustrated in (b) of FIG. 16, the pulse waveform p
corresponding to the first pulse signal fed on a coil-by-coil
basis. The pulses p1 through p9 are intermittently output to each
of the coils 21 through 24 from the output port 61, so that the
pulses of the first pulse signal are intermittently fed to each of
the coils 21 through 24. Further, the inductance detecting step is
repeated at regular intervals, so that the pulse waveform p (of the
pulses p1 through p9) of the voltage waveform V1 is output at
regular intervals. The pulse waveform p is a driving voltage for
detecting a change in the inductance of each of the coils 21
through 24.
[0076] The driving voltage V1 causes a detection voltage V3 due to
an increase in inductance to be generated as illustrated in (c) of
FIG. 16 in accordance with the amount of pressing (displacement) W
of the key 30 illustrated in (a) of FIG. 16. In the case where the
amount of pressing W varies as illustrated in (a) of FIG. 16, the
amplitude of the detection voltage V3 varies in proportion to the
amount of pressing W. The amplitude of pulses s3, s4, and s5 of the
detection voltage V3 increases as the amount of pressing W
increases, and the amplitude of pulses s6 and s7 of the detection
voltage V3 decreases as the amount of pressing W decreases. If
there is no change in the amount of pressing W, the amplitude of
the pulse waveform of the detection voltage V3 remains the same
(pulses s1, s2, s8, and s9).
[0077] Further, the method of controlling the operation input
device 1 includes a magnetic field generating step of generating
the magnetic field H to displace the operation surface 30b of the
key 30 by feeding a second pulse signal to the coils 21 through 24
on a coil-by-coil basis, the second pulse signal being different in
phase from the first pulse signal fed in the inductance detecting
step. In the magnetic field generating step, the CPU 60 outputs a
pulse waveform q (pulses q1 through q5) from the output port 61 as
the square-wave voltage waveform V1 as illustrated in (b) of FIG.
16, the pulse waveform q corresponding to the second pulse signal
fed on a coil-by-coil basis. The pulse waveform q is output to each
of the coils 21 through 24, so that the second pulse signal is fed
to teach of the coils 21 through 24. With the outputting of the
pulse waveform q, the attraction force F is generated to attract
the key 30 to the coil side as illustrated in (e) of FIG. 16.
[0078] FIG. 16 illustrates a control method that outputs pulses q1
through q5 in accordance with the amplitude of the detection
voltage V3, which is the result of detection of inductance
variations. That is, if the amplitude of the detection voltage V3
is less than a predetermined threshold, no pulse waveform q is
output. If the amplitude of the detection voltage V3 is more than
or equal to the predetermined threshold, the pulse waveform q
corresponding to the amplitude of the detection voltage V3 is
output. That is, the pulse waveform q to cause a displacement of
the operation surface 30b in accordance with the amount of pressing
W is generated with amplitude proportional to the amplitude of the
detection voltage V3. Then, the attraction force F whose magnitude
corresponds to the amplitude of the pulse waveform q is
generated.
[0079] The amplitude voltage, the pulse width, and the pulse output
period of the pulse waveform p for detecting inductance variations
may have such magnitude, size, or length as to allow detection of
inductance variations with the detection voltage V3 and to prevent
the magnetic field H capable of causing a displacement of the
operation surface 30b that may be sensed by the operator from being
generated. This makes it possible to prevent the operator from
sensing a displacement of the operation surface 30b at every
instant of detecting inductance variations. On the other hand, in
order to ensure that the operator senses a displacement of the
operation surface 30b caused by the pulse waveform q, the amplitude
voltage, the pulse width, and the pulse output period of the pulse
waveform q may have such magnitude, size, or length as to generate
the magnetic field H capable of causing a displacement of the
operation surface 30b that may be sensed by the operator. For
example, at least one of the amplitude voltage and the pulse width
of the pulse waveform q is greater than that of the pulse waveform
p.
[0080] In the case where no such measure is taken, for example, a
reset signal VR for preventing the reception circuit 67 from
operating may be generated at least during generation of the pulse
waveform q as illustrated in (d) of FIG. 16 in order to prevent the
CPU 60 from erroneously detecting the detection voltage V3
generated by the output of the pulse waveform q for providing the
operation surface 30b with a displacement as a signal representing
inductance variations. As a result, it is possible to prevent the
detection voltage V3 from being generated during the output period
of the pulse waveform q as illustrated in (c) of FIG. 16. Further,
since the pulse waveform q is output by the CPU 60, the CPU 60 may
be configured to not evaluate the detection voltage V3 generated
with the pulse waveform q as a signal representing inductance
variations (that is, ignore the detection voltage V3 generated with
the pulse waveform q).
[0081] Further, in FIG. 16, (b) indicates a control method that
outputs the pulse waveform q having amplitude corresponding to the
amount of pressing W, while such a control method is also possible
that causes a displacement of the operation surface 30b by
outputting the pulse waveform q having a pulse width corresponding
to the amount of pressing W as illustrated in (f). The pulse width
of the pulse waveform q increases as the amount of pressing W
increases.
[0082] Further, as illustrated in (g) of FIG. 16, such a control
method is also possible that causes a displacement of the operation
surface 30b by outputting the pulse waveform q whose number of
pulses corresponds to the amount of pressing W. The number of
pulses of the pulse waveform q increases as the amount of pressing
W increases.
[0083] Further, depending on applications using this operation
input device 1 (for example, electronic apparatuses used by the
operator, such as game machines and cellular phones), the pulse
waveform q does not necessarily have to be in synchronization with
the pulse waveform p. Accordingly, as illustrated in (h) of FIG.
16, a time interval for generating pulses of the pulse waveform q
(the pulse output interval of the pulse waveform q) may be changed
over multiple pulses of the pulse waveform p. The pulse waveform p
for detecting inductance variations corresponds to the temporal
resolution (slew rate) of detection of inductance variations.
Therefore, it is desirable that pulses of the pulse waveform p be
output at short time intervals. On the other hand, pulses of the
pulse waveform q for causing a displacement of the operations
surface 30b are output at longer intervals than those of the pulse
waveform p in order to cause the operator to feel occurrence of a
displacement of the operation surface 30b. For example, as
illustrated in (h) of FIG. 16, pulses q1 through q9 of the pulse
waveform q may be output in periods during which no pulses of the
pulse waveform p are output so as not to overlap pulses of the
pulse waveform p.
[0084] Further, in the case where the pulse output interval of the
pulse waveform p is too short to secure the output timing of the
pulse waveform q, the pulse waveform q may be given priority over
the pulse waveform p, and the pulse output of the pulse waveform p
may be stopped during the pulse output period of the pulse waveform
q.
[0085] Further, in the case of FIG. 16, where a displacement is
caused to the operation surface 30b in accordance with the amount
of pressing W, it is possible to change the form of vibrations
given to the operator because a change is caused in the manner in
which electric current flows through the coils 21 through 24 by
changing the form of feeding of the pulse waveform q. For example,
it is possible to change the strength of vibrations given to the
operator, a vibration frequency, and the number of vibrations by
causing a change in the manner in which electric current flows
through the coils 21 through 24 by changing the form of feeding of
the second pulse signal. Further, the timing of generation of a
displacement of the operation surface 30b may be changed not only
in accordance with the amount of pressing W, but also in accordance
with the pressing speed of the key 30 or a position to which an
object caused to move by operating the key 30 (such as a cursor or
pointer on a display) moves, or in response to occurrence of an
event in an application in which the operation input device 1 is
used. For example, the magnetic field H is generated to displace
the operation surface 30b by feeding the second pulse signal to the
coils 21 through 24 in response to the amount of pressing W of the
key 30 reaching a predetermined value. It is possible to cause the
operator to feel a click with the thus caused displacement of the
operation surface 30b.
[0086] FIG. 17 is an exploded view of an operation input device 2,
which is a second example of the operation input device of this
embodiment. FIG. 18 is a diagram illustrating that as many cores as
the number of coils placed on the placement surface 10a of the
board 10 are provided on the opposed surface 30a of the key 30
facing the board 10. FIG. 19 is a diagram illustrating the
positional relationship of the case 40, the key 30, cores 81
through 84, the coils 21 through 24, and a center key 31 viewed
along the z-axis. FIG. 20 is a diagram illustrating an arrangement
of a click spring 70 and the return springs 51 through 54. FIG. 21
is a cross-sectional view of the operation input device 2,
illustrating a state where an operator's finger is placed on the
key 30. FIG. 22 is a cross-sectional view of the operation input
device 2, illustrating a state where the key 30 is pressed at a
position in the x(-) direction. In these drawings, the same
elements as those described above are referred to by the same
reference numerals, and a description thereof is omitted.
[0087] The operation input device 2 includes the click spring 70
provided on the placement surface 10a of the board 10 at its center
portion on the z-axis surrounded by the coils 21 through 24. The
click spring 70 is a dome-shaped elastic member configured to
provide a feeling of clicking to the operator pressing the
operation surface 30b with a finger.
[0088] Further, the operation input device 2 includes the center
key 31 on the z-axis. The center key 31 is sandwiched and held
between the key 30 and the click spring 70. The center key 31 is
supported in contact with the click spring 70. This makes it
possible to reduce the thickness of the operation input device 2 in
the z-axial directions compared with the case where the center key
31 is supported without contacting the click spring 70. The center
key 31 is a press part having a surface 31b exposed at the
operation surface 30b of the key 30 on the z-axis.
[0089] The center key 31 is configured to deform the click spring
70 from the z(+) side in response to application of the operator's
force on at least one of the operation surface 30b of the key 30
and the exposed surface 31b. The click spring 70 is deformed by the
pressing of both the key 30 and the center key 31 due to the
application of the operator's force on the operation surface 30b.
The click spring 70 is also deformed by the pressing of the center
key 31 without the pressing of the key 30 due to the application of
the operator's force on not the operation surface 30b but the
exposed surface 31b. The center key 31 is positioned by being fit
into a through hole 30c open at both the operation surface 30b and
the opposed surface 30a of the key 30. The center key 31 may be
circular, elliptical, or polygonal.
[0090] For example, the center key 31 includes a flange 31a formed
at its edge. The flange 31a is a step part protruding like a brim
at the edge of the center key 31. The center key 31 is held by
being sandwiched between the opposed lower surface 30a of the key
30 and the top of the click spring 70 with the flange 31a being in
contact with the key 30 in the periphery of the through hole
(center hole) 30c. The portion of the center key 31 fit into the
through hole 30c, which portion includes the exposed surface 31b,
is held by the through hole (center hole) 30c serving as a guide.
The operator may touch the exposed surface 31b. The operation
surface 30b of the key 30 and the exposed surface 31b of the center
key 31 in the standby state may be at the same position in the
z-axial directions. Alternatively, the position of the operation
surface 30b may be closer to the board 10 than the position of the
exposed surface 31b is in the z-axial directions. In this case, the
operator's force is applied on the exposed surface 31b of the
center key 31 without being applied on the operation surface 30a of
the key 30, so that the position of the exposed surface 31b moves
in the direction in which the force is applied relative to the
operation surface 30b with the operations surface 30b remaining at
the same position in the z-axial directions.
[0091] As illustrated in FIG. 17 through FIG. 19, the four cores 81
through 84 are connected to the opposed surface 30a of the key 30
so as to move vertically in the same direction as the key 30 when
the key 30 vertically moves. The cores 81 through 84 are inductance
increasing members that increase the absolute value of the
inductance of at least one of the coils 21 through 24. The cores 81
through 84 are placed at positions facing the coils 21 through 24,
respectively. The outside diameter of the cores 81 through 84 is
smaller than the inside diameter of the coils 21 through 24.
[0092] As illustrated in FIG. 20, the return springs 51, 52, 53,
and 54 may be provided on the placement surface 10a of the board 10
so as to surround the coils 21 through 24.
[0093] FIG. 21 and FIG. 22 are diagrams for illustrating states of
the operation input device 2 at the time of the operator operating
the operation input device 2.
[0094] In FIG. 21 and FIG. 22, the center key 31 is in contact with
the top of the click spring 70 and is held at the through hole
(center hole) 30c of the key 30. The key 30 is held by the return
springs 51 through 54 (FIG. 20) to be prevented from falling
downward. Therefore, pressing the center key 31 with a finger
causes the center key 31 to move downward independently to deform
the click spring 70, thereby giving a feeling of clicking to the
fingertip and closing contacts for detecting the pressing of the
center key 31. That is, the click spring 70 operates as a
switch.
[0095] In FIG. 22, pressing a portion of the key 30 around the
through hole 30c, into which the center key 31 is fit, causes the
key 30 to move downward deforming the return springs 51 through 54.
At this point, since the center key 31 includes the flange 31a, the
center key 31 also moves downward in conjunction with the downward
movement of the key 30.
[0096] As illustrated in FIG. 21, in the standby (initial) state
where the key 30 is not pressed, the cores 81 through 84 are
positioned above the coils 21 through 24, respectively. Then, as
illustrated in FIG. 22, when the key 30 is pressed, the cores 81
through 84 enter the coils 21 through 24, respectively, without
contacting the coils 21 through 24 as the key 30 moves downward.
The entry of the cores 81 through 84 into the corresponding coils
21 through 24 increases the magnetic permeability around the coils
21 through 24 to increase their inductance. In particular, the
ambient magnetic permeability of the coil 23 among the four coils
21 through 24 increases to increase the inductance of the coil 23
since a force is applied on the operation surface 30b above the
coil 23.
[0097] This change in inductance is detected with, for example, the
inductance detecting circuit 100 illustrated in FIG. 13. On the
other hand, the center key 31 that has moved downward in
conjunction with the key 30 deforms the click spring 70, thereby
giving a feeling of clicking to the fingertip and closing a switch
caused to operate by the click spring 70. Then, like in the
operation input device 1, the first pulse signal and the second
pulse signal may be fed to each of the coils 21 through 24 by, for
example, the control method illustrated with the waveform chart of
FIG. 16 in the operation input device 2 as well.
[0098] Therefore, according to the second example, the magnetic
permeability in the standby (initial) state of no application of
force by the operator may be higher than in the case without a
core, so that the absolute value of inductance may be higher. This
effect makes it possible to reduce the height of coils and
accordingly to reduce the thickness of the operation input device
in the z-axial directions. Further, the gradient of an increase in
inductance at the time of entry of a core into a coil is greater
than in the case of being merely approached by a yoke, so that it
is possible to increase sensitivity to the amount of pressing of
the operation surface. Further, since it is possible to vary
inductance with the movement of a core, it is possible to easily
detect inductance variations without the key 30 having the function
of a yoke. Accordingly, it is possible to form the key 30 with a
nonmagnetic material. Further, since the core is not thin like a
yoke and has a structure free of stress application, a fragile
material such as ferrite may be used for the core.
[0099] Thus, according to the above-described examples, it is
possible to generate a magnetic field to displace the operation
surface by feeding a coil fed with a first pulse current for
detecting an operator's operation input with a second pulse current
different in phase from the first pulse current. Therefore, it is
possible to implement the function of detecting an operator's force
and the function of providing vibrations to the operator with an
extremely simple configuration.
[0100] All examples and conditional language recited herein are
intended for pedagogical purposes to aid the reader in
understanding the invention and the concepts contributed by the
inventor to furthering the art, and are to be construed as being
without limitation to such specifically recited examples and
conditions, nor does the organization of such examples in the
specification relate to a showing of the superiority or inferiority
of the invention. Although the embodiment of the present inventions
has been described in detail, it should be understood that various
changes, substitutions, and alterations could be made hereto
without departing from the spirit and scope of the invention.
[0101] That is, other examples of the operation input device and
the operation input detecting device of this embodiment may be
implemented by combining the above-described examples.
[0102] Further, the operation input device may be configured to be
operated by not only a finger but also a palm. The operation input
device may also be configured to be operated by a toe or a sole.
Further, the operation surface 30b of the key 30 may be flat,
concave, or convex.
[0103] Further, in FIG. 7, a change may be caused elastically in
the interval (distance) between the opposed surface 30a of the key
30 and the placement surface 10a of the board 10 by application of
the operator's force, for example. Alternatively, a change may be
caused elastically in the interval (distance) between the opposed
surface 30a of the key 30 and the placement surface 10a of the
board 10 by the deflection of the case 40 due to application of the
operator's force.
* * * * *